Portable : USB

Foldable, flexible portable USB solar panels, providing 5V USB output for phones, mp3 players, GPS receivers, and more.

Now that there are so many devices that operate in the USB-realm, these panels are finding all sorts of new uses. Most of the more powerful models can charge fussy smart phones directly, while all of them will trickle-charge a USB back-up battery which can in turn charge one or several devices at once even after the sun goes down.